Generally, a cyclone dust collector in a vacuum cleaner draws in dust-laden air, forms a whirling or cyclonic air current that separates dust from the dust-laden air by a centrifugal force generated from the whirling air current and collects the separated dust particles in a bin or trap for later disposal. In general, cyclone dust collectors do not pass dust-laden air through an air filtration element.
FIGS. 1 and 2 are respectively, a perspective view and a cross-sectional view, of a prior art conventional cyclone dust collector. As shown in the drawings, the cyclone dust collector comprises a cyclone body 10, a suction port 11 for drawing in air, a discharge port 12 for discharging dust-separated air, a grill member 13 connected to the discharge port 12, and a dust receptacle 14.
The suction port 11 guides dust-laden air drawn in from a surface being cleaned, into the cyclone body 10. As shown in FIG. 2, the suction port 11 is tangentially connected to an inner circumference of the cyclone body 10. The drawn-in air forms a whirling, i.e., cyclonic air current flowing along the inner circumference of the cyclone body 10, as shown by an arrow in FIG. 2. Dust particles that are suspended in the air are centrifuged. Since a suction force is generated by a vacuum suction means (not shown) in the grill member 13, however, the air drawn in from the suction port 11 may fail to generate the whirling air current before being discharged through the discharge port 12. In such a case, the centrifuged dust may not be collected in the dust receptacle 14 but stuck to the grill member 13 instead, thereby deteriorating suction strength and reducing the effectiveness of the cyclone dust collector.
Furthermore, turbulence in the air flow in the cyclone body 10, which can be generated in the cyclone dust collector for many reasons, also affects dust separation. Air flow direction changes and air current collisions are just two things that can weaken the cyclone, i.e., reduce its rotational speed, thereby reducing the centrifugal force exerted on suspend dust particles. More specifically, since the cyclone body 10 has a substantially cylindrical form for smooth flow of the whirling air current, the air drawn into the cyclone body 10 through the suction port 11 undergoes sudden change in its path, accordingly forming a turbulent flow by its own inertia. In addition, as it enters the cyclone dust collector, the air drawn in through the suction port 11 collides with the whirling air current formed in the cyclone dust collector, thereby causing the turbulent flow especially in a spot S shown as a hatched area in FIG. 2. In addition, because the turbulent flow scatters away the dust already centrifuged, dust collection diminishes. A cyclone dust collector that avoids the problems created by prior art grill elements would be an improvement over the prior art.